Beam Loss Monitors and Ion Chambers for protecting Hall Equipment Tommy Michaelides (SSG) Stay Treat 2016

Beam Loss Monitor What is a Beam Loss Monitor? In terms of MPS Photomultiplier tube – Converts light (photons) into an electrical current Pros: High Sensitivity Fast rise times Reliable and easy to diagnose Does not require active beam for testing Cons: Some fault trips due to secondary emissions or other factors Susceptible to radiation damage with aging in the field

BLM Hall Equipment Protection BLMs are mostly used in the transport region Some experiments may require BLMs beyond the transport region New BLMs for Hall B to protect the Si detectors Problems with current installation configuration The nearest HVPS is located on the CH second floor, sometimes the BSY HVPS is utilized Similar problem with the data acquisition circuits Currently using local HVPS from Physics to support BLMs (Hall B – Not fail safe) Shared resources for multiple halls Would like to install MPS HVPS and DAQ in each hall Make use of the VME CAEN HV cards and BLM cards

Ion Chambers What is an Ion Chamber? In terms of MPS Pressurized tube - Converts the radiation (gamma) caused by electrons striking beam line components into electrical current Pros: Long recovering times (Steady State Signal) Resistance to damage from radiation Reliable Cons: Slow rise time (Not optimum for counters) Low Sensitivity Requires active beam for testing and calibration

IC Hall Equipment Protection Ion Chambers throughout hall beam line Where to mount it? Often one of the most complex questions Need more active involvement from physics What should it protect? Not always well specified Define it prior to the experiment set up What level of losses are we expecting to measure? Ion Chambers are not as sensitive as BLM’s Cannot control dynamic range with HV

Hall D 12Gev Third generation Ion Chamber system New VME Electronics with diagnostics and adjustable integrator trip points Rad hard CERN Ion Chamber CAEN HV power supply with excellent diagnostics and fault indicators. Would like to replicate in Hall A & C in the near future Currently using legacy “refrigerator” system with limited channels and flexibility. Michaelides

Calibration & Configuration When should we perform a calibration test on hall Ion Chambers? Every time we change a target Prior to running beam or after long shut downs Would it be useful to generate automatic trip points for every target? Or a group of targets? Operations is working on requirements Benefits: Ensuring accurate set points when changing the current Ensuring accurate set points when changing targets

Availability of the IC System Upgrades that increase availability in the legacy system Replace all the signal and HV cables Improve temperature control for the electronics Centralize location for the black boxes (HV supplies) Testing each Ion Chamber prior to field installation (Radcon calibration lab) Calibrating each amplification card prior to operation

Reliability of the IC System Upgrades that increase reliability in the legacy system Implementation of a fail safe HV signal (black boxes) The FSD signal is now directly driven by the amplification board Ensuring that the calibration procedure and the functional test is perform prior to running beam

Discussion/Questions